This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an example described below, more particularly provides a retrievable swellable packer.
It is known to use a swellable seal element on a packer for sealing off an annulus in a well. During or after installation of the packer in the well, a certain fluid is placed in contact with a swellable material, causing the material to increase in volume and thereby extend the seal element into sealing contact with a structure (such as, a casing, tubing, wellbore, etc.).
However, such packers have not been conveniently retrievable from wells in the past. The seal element is designed to resist degradation in the well environment, and so it is difficult to devise a means of releasing the seal element from its contact with the structure in the well.
Therefore, it will be appreciated that improvements are needed in the art. Such improvements would preferably allow for convenient retrieval of a swellable packer from a well after having been set in the well, but the improvements may be useful in other applications, as well.